How to create a composite key based on foreign keys?

I’m trying to create the entities and their relationships like in the ERD above.

User entity

import {Entity, PrimaryColumn, Column, CreateDateColumn, UpdateDateColumn} from "typeorm"`

@Entity()
export class User {

    @PrimaryColumn()
    id: string;

    @Column( { type: "string", unique: true } )
    IGN: string;

    @Column()
    age: number;

    @CreateDateColumn()
    created_at: Date;

    @UpdateDateColumn()
    updated_at: Date;
}

Achievement entity

import {Entity, PrimaryGeneratedColumn, Column, CreateDateColumn, UpdateDateColumn} from "typeorm";

@Entity()
export class Achievement {

    @PrimaryGeneratedColumn()
    id: string;

    @Column( { type: "text", unique: true } )
    name: string;

    @Column()
    description: string;

    @CreateDateColumn()
    created_at: Date;

    @UpdateDateColumn()
    updated_at: Date;
}

I’m having hard time to make the user_achievement entity. Since it has foreign keys that need to be turned into composite keys. How can I accomplish this?

[onkarjit]

I did the following to accomplish this:

UserAchievement

import {CreateDateColumn, Entity, ManyToOne, JoinColumn, PrimaryColumn} from "typeorm";
import { User } from "./User";
import { Achievement } from "./Achievement";

@Entity()
export class UserAchievement {
    @PrimaryColumn()
    user_id: string;

    @PrimaryColumn()
    achievement_id: number;

    @ManyToOne(type => User, user => user.id)
    @JoinColumn({ name: "user_id" })
    public user!: User;

    @ManyToOne(type => Achievement, achievement => achievement.id)
    @JoinColumn({ name: "achievement_id" })
    public achievement!: Achievement;

    @CreateDateColumn()
    created_at: Date;
}

I’m only unsure now if this is the correct way to turn my foreign keys into composite keys.

[tareqdayya]

And it seems you can also set primary option to true inside the relation options. This way you wouldn’t have to use the @PrimaryColumn decorator: @ManyToOne( () => Author, (author) => author.id, { primary: true, }, )